1. Field of the Invention
This invention relates to an input display apparatus comprising a display means such as a cathode ray tube (CRT) or the like, and a transparent touch panel superposed on the display means and provided with touch key elements.
2. Description of the Prior Art
Although the input display apparatus of this invention can be used for other applications, it is most suitable for an injection molding machine for molding products having a relatively large thickness, precise dimensions and a small internal strain such as optical lenses. The invention will be described as applied to such an injection molding machine.
A copending U.S. patent application Ser. No. 140,145, filed on Dec. 29, 1987 discloses a method and apparatus for injection compression molding of the type described above.
The apparatus for operating an injection compression molding machine described in the U.S. patent application comprises a stationary metal mold, a movable metal mold, an oil pressure actuator for advancing the movable metal mold toward the stationary metal mold to form a mold cavity therebetween with a predetermined compression clearance .delta. between the movable and stationary metal molds, a heating cylinder engaging the stationary metal mold, means for supplying a thermoplastic resin into the heating cylinder, a screw contained in the heating cylinder for injecting molten resin into the mold cavity, means for rotating the screws, means for reciprocating the screw in the heating cylinder, a screw position detector for detecting an axial position of the screw, a plurality of screw position setters respectively setting predetermined screw positions along which the screw is moved, a plurality of comparators respectively comparing output signals of the screw position setters with the output signal of the screw position detector, a plurality of mold clamping force setters connected to receive output signals of respective comparators, a transfer switch for selecting one of the output signals of the mold clamping force setters, and an electromagnetic transfer valve energized by an output signal of the transfer switch through a control device for actuating the oil pressure actuator. There is also provided a timer for setting the rotation time of the screw, which determines the filling time of the molten resin.
The injection compression molding machine described above operates as follows. When the filling step is completed, the screw reaches the forward limit position. Then the metal molds are opened by moving the movable metal mold to take out the molded product. After that, metal molds are partially closed while leaving a predetermined compression clearance .delta. therebetween. For preparing the next filling step, the molten resin is stored in the heating cylinder in front of the screw by rotating the same. Then the screw is retracted by the cylinder while being rotated by the oil pressure motor. When the screw position detector detects a predetermined screw position, a signal is issued so that the electromagnetic transfer valve is moved to a position to block the pressurized oil discharged from the injection cylinder. Consequently, the screw continues to rotate at that predetermined position, whereby the molten resin is accumulated in the space in front of the screw for an interval set by the timer. After lapse of a time set by the timer, the electromagnetic transfer valve is brought to a position for advancing the screw by the injection cylinder so as to inject the molten resin accumulated in the space in front of the screw into the mold cavity under a high pressure. As the screw reaches a predetermined position, for example a position set by the screw position setter, and during the injection stroke, the mold clamping cylinder is actuated to clamp together the stationary and movable metal molds so as to decrease the clearance .delta.. Consequently, the problem of insufficient quantity of the injected resin at each shot and the problem of creating internal stress can be solved.
In an injection molding apparatus, and especially in the described injection compression molding apparatus, it is advantageous to provide a transparent touch panel superposed on the display member and provided with a plurality of touch key elements. A prior art input display device utilizing touch keys, as shown in FIGS. 3 and 4, comprises a touch panel 50 including a timer display setting member 10, an injection filling pressure display setter 11, an injection speed display setter 12, an injection speed changing position display setter 13, and other items. These are all labels for numerical machine parameters which can be changed by the display device, and shall hereafter be called set display labels. The corresponding displayed parameter number shall be referred to as a set data item. The transparent touch panel 50 is superposed on the face plate 51 of a CRT. The timer display setting portion 10 includes a plurality of timer setting means 14 including pressure holding timers TR1, TRH3, TRH2 and TRH1 which marked by set display labels, and a plurality of set display items 15 (in this case 15.0 sec., 2.0 sec., 0.00 sec. and 3.0 sec. respectively representing the times of timers TR1 . . . TRH1). The injection filling pressure portion 11 of the CRT depicts a SLOPE of a holding pressure, pressures held PH4, PH3, PH2, PH1 and final pressure FILP and their values in percentages 20, 60 and 40 of their maximum values. The final pressure FILP is set as 140% because such high pressure is necessary to inject the resin into an intricated mold cavity. Arrows between the blocks show related timer times and corresponding pressures to be held. The injection speed display portion 12 includes pressure HOLD, SLOPE, positions V14, V13, V12, V11 representing the positions at which the injection speed is changed and speeds in % of the maximum speed at respective positions. The injection speed changing portion 13 includes screw position detection limit switches LS4, LS4C, LS4B, LS4A, LS5, LS10, and strokes 2.0-0.0 and 200.0 each in mm in which 200.0 indicates the retracted position of the screw. The bottom portion of the CRT includes the numbers of screw revolutions SR, screw back pressure BP, metering control condition program PROG, RESIN (raw material code), SLOPE, their values 80, etc., quantity of charge CHARGE, OFF and DROOL which occurs when the nozzle is slightly separated from the stationary metal mold. It should be understood that most of these set display labels displayed on the CRT, correspond to a touch key, and that when these touch keys are depressed, the machine parameter corresponding to the selected set display label can be inputted or changed by a ten key 16, as shown in FIG. 4. The ten key 16 is located in the area of face plate 51 of the CRT. In this manner, by selectively operating the desired touch keys, the result of the operation can be observed on the face plate.
Where the ten key is remote from the CRT, as shown in FIG. 3, the set data displays 15 and the ten-key are separated and the setting operation becomes more difficult. If the ten key is included in a portion of the transparent touch panel, as shown in FIG. 4, only the area of the CRT excluding the ten key can be used as the data display area. As a consequence, where it is desired to display all related data on the same display apparatus the number of displayed input data items would be limited. Furthermore, where a ten key is used to input the data, it is necessary to input every digit. This is true even when an operator desires to change only one digit of an input data item. For example, when it is desired to change a setting of 201.5 to 211.5, the values of all the digits must be inputted. This is both troublesome and time consuming.